There are three fundamental forces that act at a distance. They are gravitational, electromagnetic and nuclear forces.
Answer:
Hear echo sooner on a hot day than on a cooler day.
Explanation:
Temperature is one of the factors that determine the speed of sound. Speed of sound, which in this case is echo is calculated considering distance and time. Speed of sound is directly proportional to the temperature , therefore, when the temperature is hot, the speed of sound is faster than when the temperature is cold and vice versa. In conclusion, you would expect to hear the echo “hello” sooner on a hot day compared to a cold day provided all the other factors are kept constant.
The average daily annual temperature range is exceeded in places such as deserts. Deserts tend to be hotter due to the lack of water contained within them. This means that all of the sun's thermal radiation heats up the ground and air. These factors cause deserts to have above average temperatures.
Answer:
A. 0.0096 W/m²
B. 11.603 dB
C. 827.37 m/s
Explanation:
Parameters given:
Frequency, f = 274Hz
Pressure, P = 101.3 kPa
Temperature, T = 25°C = 298K
Power = 30 mW
Radial distance, = 500 mm = 0.5 m
A. Intensity = Power/Area
Intensity = Power/(4*pi*r²)
= (30 * 10^(-3))/(4 * 3.142 * 0.5²)
= 0.0096 W/m²
B. Pressure(rms) = √(I*ρ*c)
I = Intensity
ρ = density
c = speed of sound
ρ = P/RT
R = gas constant
=> ρ = (101.3 * 10^3) / (298 * 8.314)
ρ = 40.89 kg/m³
=> Pressure(rms) = √(0.0096 * 40.89 * 343)
= √(134.64)
= 11.603 dB = 11.603 * 10^(-6) Pa
C. Acoustic Particle velocity = Intensity/ Acoustic Pressure
Acoustic Particle velocity = 0.0096 / (11.603 * 10^(-6)
Acoustic Particle velocity = 827.37 m/s
The atmosphere<span> can be </span>divided into<span> four </span>layers<span> based on temperature variations. The </span>layer<span> closest to the Earth is called the troposphere. Above this </span>layer<span> is the stratosphere, followed by the mesosphere, then the thermosphere.</span>
